It is known that air swirling devices of internal combustion engines and the likes can provide a large amount of air of high density to a combustion chamber of the engine by adding revolution force to airflows provided into the combustion chamber of the internal combustion engine and increasing the speed of airflow per unit time, so that combustion action of the engine is improved and engine power is increased. The prior arts have a disadvantage that air resistance generated when airflow is rotated cannot be prevented completely.
For example, Japanese patent publication Nos. 53-26247, 59-11722 and U.S. Pat. No. 4,309,969 disclose a simple turbulence device, which includes an intake valve having a large intake resistance, so that the swirling device does not create uniform airflow but create only turbulent flow.
Also, Japanese Patent Publication Nos. 60-17922 and 61-10645, and U.S. Pat. Nos. 4,424,777, 4,432,312 and 4,539,954 disclose a swirling device having wings which are disposed near an intake valve for swirling airflow.
However, such a device exhibits high friction so that the device provides a reduced amount of inlet air and thus is used only for a gasoline engine of the carburetor type.
To solve the above problems, U.S. Pat. No. 4,962,642 discloses an air swirling device having a plurality of wings positioned within an air cleaner of an internal combustion engine for swirling the airflow into the combustion chamber, so that combustion performance and engine power can be improved. However, such device has some disadvantages, such as for example, reduced output of the engine due to reduced inlet air and loss of fuel because of eddy generated at a rear surface (negative pressure zone) of the wings when the air flow is swirled.
To solve the above problems, Korean Utility Model Reg. No. 67786 issued to the inventor of this invention discloses a swirling device including an swirling device body 10 provided with a plurality of wings 11 having at least one or more generally thin, long slits 12, as shown in FIGS. 1 and 2. The swirling device body 10 is fixed and mounted in the vicinity of the center of an air cleaner 13 with bolts and nuts for swirling intake air, so that eddy generated at the negative pressure zone formed on the rear surface of the wings 11 with the slits 12 when the air enters, is prevented. As the result, air resistance is reduced and the amount of airflow is increased, so that a complete combustion is attained to improve energy efficiency and engine power.
As shown in FIG. 1, the swirling device with the slits 12 formed in the wings 11 thereof adds a revolution force to the airflow induced into a combustion chamber 14, so that the speed of airflow per unit time is increased and the density of the air flow becomes high to improve an combustion action. During an intake operation of the internal combustion engine caused by the slits 12 formed in the wings 11, the air filtered through the air cleaner 13 passes and rotates through the slits 12 formed in the wings 11 of the swirling device body 10 mounted in the air cleaner 13. The rotated airflow is swirled again by another air swirling device 16 mounted near an inlet of an intake manifold 15 and provided into the combustion chamber 14 at a high speed. The combusted exhaust gas is rapidly discharged by still another air swirling device 18 mounted near an inlet of an exhaust manifold 17;
Because the swirling device of the internal combustion engine has at least one or more slits 12 in the plurality of wings 11, eddy generation at the negative pressure zone of the rear surfaces of the wings is reduced. When the swirling device is placed in the air cleaner 13, the carbon monoxide (CO) gas level can be reduced up to about 17% at engine idle speed, the engine power can be increased up to about 11%, fuel economy can be improved to about 6%, and knocking of the engine can be reduced up to about 5%.
Therefore, the swirling device of the internal combustion engine having the slits 12 in the wings 11 adds the revolution force to the airflow induced into the combustion chamber, so that the speed of air flow per unit time is increased and combustion action, due to the increased density, is improved. Furthermore, in the swirling device of the internal combustion engine, eddy generation at the negative pressure zone by the slits 12 formed in the wings 11 is prevented, and thereby, the airflow resistance is reduced and the amount of airflow is increased, so that a sufficient amount of accelerated air is provided into the engine to increase its combustion efficiency and engine power.
However, the slits 12 formed in the wings 11 of the conventional swirling device of the internal combustion engine are not ideal in reducing eddy, because of being formed by cutting portions of the flat sheet type wings 11 to have a generally thin and long shape. According to such circumstances, the conventional swirling device of the internal combustion engine having the slits 12 formed in the wings 11 cannot cope with more controlled airflow.
For example, the conventional swirling device of the internal combustion engine having the slits 12 formed in the wings 11 increases the speed of airflow per unit time and raises density of air by adding revolution force to the airflow induced into the combustion chamber, so that the combustion action and the engine power are improved. However, only a swirling device cannot control airflow conditions because a supercharging of the air by the swirling device may occur.
Moreover, in the conventional swirling device, the thin and long rectangular slits 12 are not made uniformly, and in case where the slits 12 are cut in a length direction, there is a possibility that the wings 11 may be deformed, which makes the air flows substantially decelerated.
Additionally, because the shape of the wings for preventing eddy generation at the negative pressure zone by forming the slits 12 in the wings 11, induces linear type of airflow due to their flat upper and lower sides, it is difficult to maintain a stably and uniformly mixed level of the air and fuel particles and to secure a sufficient amount of airflow.
FIG. 3 shows the air dispersion on the surface of the wing 11 with the slit 12. In other words, the airflow loses their direct streams and as soon as they are against the surface of the wing 11, they are dispersed in every direction. Generally, the dispersed airflow on the surface of the swirling wing 11 make the speed of airflow substantially decreased, which results in the decrease of the amount of airflow. This means that the object of the installation of the wings for increasing the amount of airflow is not achieved. This also accompanies the deterioration of the engine performance, the low efficiency of energy, the serious air pollution and so on. It is therefore appreciated that the conventional swirling device having the wings 11 each provided with the slit 12 fails to sufficiently compensate for the amount of air flow.
Until now, the eddy effect from the internal combustion engine has been emphasized, but the conventional swirling devices has a problem that as the airflow are against the wings and dispersed in every direction, it is difficult to maintain the airflow in a smooth manner.